As antivibration devices supporting a vibration source like an engine or the like on a vehicle body, there is known an antivibration device disclosed in Patent Literature 1, for example. In the antivibration device disclosed in Patent Literature 1, a shaft-like first fixture and a sleeve-like second fixture are connected by an antivibration base body including a rubber elastic body. At a portion joined to the antivibration base body of the first fixture, a first projection plane made by being projected in a first direction orthogonal to the axis is smaller in area than a second projection plane made by being projected in a second direction orthogonal to the axis and the first direction. Thus, it is possible to make a spring constant in the first direction smaller than that in the second direction.